Hash tags (Things to know) for each lecture…


  • Use these as your study guides. Each one is a concept (not a definition).
    • I use these concepts to write the exam/quiz questions
    • Generally, you should be able to write 2-3 sentences about each # (with no notes)
    • Create a checklist - cross them off as you study
    • Use student hours (or email) for ones you don’t quite get
    • Start with #s and expand outward when studying
    • Extra Credit Mastery Cards are based on these


#Fossil Clues


#Early Evolution Theories


#Shared Ancestry

What is evolution?


Sedimentary rocks reveal the vastness of geologic time


Fossils buried in those rocks tell the evolutionary story of life on Earth…

  • Geology and fossils reveal key facts:
  1. The Earth and life on Earth are billions of years old
  2. Fossils look very different across geologic time

Georges Cuvier (1769-1832): The concept of extinction


Cuvier’s findings refute the idea of species permanence

99% of all species that have existed have already gone extinct!!!


Scientists after Cuvier (i.e., Darwin) now had to account for extinction as fact



















Example: Wooly Mammoths appear and then disappear in the fossil record.

Jean-Baptiste de Lamarck: Famous for being wrong



  • Lines of descent (early evolution theory)
    • compared living giraffes with fossil forms
    • evolution = ‘life evolves from simple to more complex’ as organisms passed developed characteristics to their offspring


  • (1) Theory of use and disuse
    • body parts used: enhanced
    • body parts disused: minimized


  • (2) Inheritance of acquired characteristics
    • changes can be passed to offspring


  • The long muscular neck of Giraffes…

According it Lamarck, Skee-Lo could get his wish


I wish I was like six-foot-nine so I can get with Leoshi…

Transitional Forms Exist in the Fossil Record




  • There appear to be connections between living things and fossils
    • Lamarck and Cuvier
    • argues against species permanence


  • Aquatic mammals: past and present
    • nostrils
    • pelvis
    • hind limbs!
    • unique skulls

Vestigial traits: leftover structures that have lost their function


Vestigial traits: leftover structures


Traits connections argue for Shared Ancestry


Evolution as descent with modification



The fossil record lets us explore the ancestors that anything living (including us) evolved from







  • Next Time: How did giraffes really evolve longer necks?